scholarly journals Optimization of selective laser-induced etching (SLE) for fabrication of 3D glass microfluidic device with multi-layer micro channels

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Sungil Kim ◽  
Jeongtae Kim ◽  
Yeun-Ho Joung ◽  
Sanghoon Ahn ◽  
Jiyeon Choi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Microfluidic Channel ◽  
Design Guidelines ◽  
Process Window ◽  
Microfluidic Channels ◽  
Micro Channels ◽  
Scan Speed ◽  
Energy Pulse ◽  
Laser Induced Etching ◽  
Etching Selectivity

Abstract We present the selective laser-induced etching (SLE) process and design guidelines for the fabrication of three-dimensional (3D) microfluidic channels in a glass. The SLE process consisting of laser direct patterning and wet chemical etching uses different etch rates between the laser modified area and the unmodified area. The etch selectivity is an important factor for the processing speed and the fabrication resolution of the 3D structures. In order to obtain the maximum etching selectivity, we investigated the process window of the SLE process: the laser pulse energy, pulse repetition rate, and scan speed. When using potassium hydroxide (KOH) as a wet etchant, the maximum etch rate of the laser-modified glass was obtained to be 166 μm/h, exhibiting the highest selectivity about 333 respect to the pristine glass. Based on the optimized process window, a 3D microfluidic channel branching to three multilayered channels was successfully fabricated in a 4 mm-thick glass. In addition, appropriate design guidelines for preventing cracks in a glass and calibrating the position of the dimension of the hollow channels were studied.

Manufacturing of Submicrofluidic Channels Based on Near-field Electrospinning with PEO

2020 ◽  
Vol 12 (3) ◽  
pp. 243-246
Author(s):  
Jiarong Zhang ◽  
Han Wang ◽  
Zhifeng Wang ◽  
Honghui Yao ◽  
Guojie Xu ◽  
...  
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Microfluidic Channels ◽  
Direct Writing ◽  
Micro Electro Mechanical Systems ◽  
Three Dimensional Printing ◽  
Complex Process ◽  
Pdms Molding ◽  
Dimensional Printing

Background: Microfluidic channels have been widely applied in biomedicine and microelectronics. However, the manufacturing methods of microfluidic channel devices, such as photolithography, three-dimensional printing and Melt-electrospinning direct writing (MEDW), have the problem of high cost and complex process, which still can't reach a sub-micron scale stably. Method: To improve the resolution of microfluidic channels, we developed a simple and flexible method to fabricate polydimethylsiloxane (PDMS) submicrofluidic channels. It depends on the following steps: (1) Direct Writing Polyethylene oxide (PEO) nanofiber by Near-field Electrospinning (NFES). (2) Packaging the nanofiber with PDMS. (3) Obtaining the PDMS submicrofluidic channel by inverted mode of PEO nanofiber. Results: According to the result of the experiment, nanofiber can be stably prepared under the following conditions, the electrode-to-collector distance of 3.0 mm, the voltage of 1.7 KV, the collector moving speed of 80mm/s and the mixed solutions of ethanol and deionized water (1:1). Finally, the PDMS submicrofluidic channel was manufactured by NFES and PDMS molding technique, and the diameter of the channel was 0.84±0.08 μm. Conclusion: The result verified the rationality of that method. In addition, the method can be easily integrated with high resolution channels for various usages, such as microelectronics, micro electro mechanical systems, and biomedical.

scholarly journals Direct Bioprinting of Vessel-Like Tubular Microfluidic Channels

2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Yahui Zhang ◽  
Yin Yu ◽  
Ibrahim T. Ozbolat
Keyword(s):  
Tissue Engineering ◽  
Complex Structure ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Great Promise ◽  
Microfluidic Channels ◽  
Vascular Networks ◽  
Channel Network ◽  
Organ Printing ◽  
Chitosan Hydrogels

Despite the progress in tissue engineering, several challenges must be addressed for organ printing to become a reality. The most critical challenge is the integration of a vascular network, which is also a problem that the majority of tissue engineering technologies are facing. An embedded microfluidic channel network is probably the most promising solution to this problem. However, the available microfluidic channel fabrication technologies either have difficulty achieving a three-dimensional complex structure or are difficult to integrate within cell printing process in tandem. In this paper, a novel printable vessel-like microfluidic channel fabrication method is introduced that enables direct bioprinting of cellular microfluidic channels in form of hollow tubes. Alginate and chitosan hydrogels were used to fabricate microfluidic channels showing the versatility of the process. Geometric characterization was performed to understand effect of biomaterial and its flow rheology on geometric properties. Microfluidic channels were printed and embedded within bulk hydrogel to test their functionality through perfusion of cell type oxygenized media. Cell viability experiments were conducted and showed great promise of the microfluidic channels for development of vascular networks.

scholarly journals Design Methodology of Passive In-Line Relays for Molecular Communication in Flow-Induced Microfluidic Channel

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 65
Author(s):  
Puneet Manocha ◽  
Gitanjali Chandwani
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Microfluidic Channel ◽  
Microfluidic Channels ◽  
Molecular Communication ◽  
External Energy ◽  
Lab On Chip ◽  
Molecular Communication Systems ◽  
Macro Scale ◽  
On Chip

Molecular communication is a bioinspired communication that enables macro-scale, micro-scale and nano-scale devices to communicate with each other. The molecular communication system is prone to severe signal attenuation, dispersion and delay, which leads to performance degradation as the distance between two communicating devices increases. To mitigate these challenges, relays are used to establish reliable communication in microfluidic channels. Relay assisted molecular communication systems can also enable interconnection among various entities of the lab-on-chip for sharing information. Various relaying schemes have been proposed for reliable molecular communication systems, most of which lack practical feasibility. Thus, it is essential to design and develop relays that can be practically incorporated into the microfluidic channel. This paper presents a novel design of passive in-line relay for molecular communication system that can be easily embedded in the microfluidic channel and operate without external energy. Results show that geometric modification in the microfluidic channel can act as a relay and restore the degraded signal up-to 28%.

Transient Analysis of a Ceramic High Temperature Heat Exchanger and Chemical Decomposer

2007 ◽  
Author(s):  
Valery Ponyavin ◽  
Taha Mohamed ◽  
Mohamed Trabia ◽  
Yitung Chen ◽  
Anthony E. Hechanova
Keyword(s):  
Steady State ◽  
High Temperature ◽  
Heat Exchanger ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Failure Criteria ◽  
Operating Conditions ◽  
Finite Element Software ◽  
Micro Channels ◽  
Temperature Heat

Ceramics are suitable for use in high temperature applications as well as corrosive environment. These characteristics were the reason behind selection silicone carbide for a high temperature heat exchanger and chemical decomposer, which is a part of the Sulphur-Iodine (SI) thermo-chemical cycle. The heat exchanger is expected to operate in the range of 950°C. The proposed design is manufactured using fused ceramic layers that allow creation of micro-channels with dimensions below one millimeter. A proper design of the heat exchanges requires considering possibilities of failure due to stresses under both steady state and transient conditions. Temperature gradients within the heat exchanger ceramic components induce thermal stresses that dominate other stresses. A three-dimensional computational model is developed to investigate the fluid flow, heat transfer and stresses in the decomposer. Temperature distribution in the solid is imported to finite element software and used with pressure loads for stress analysis. The stress results are used to calculate probability of failure based on Weibull failure criteria. Earlier analysis showed that stress results at steady state operating conditions are satisfactory. The focus of this paper is to consider stresses that are induced during transient scenarios. In particular, the cases of startup and shutdown of the heat exchanger are considered. The paper presents an evaluation of the stresses in these two cases.

FABRICATION OF PYRAMIDAL CAVITY STRUCTURE WITH MICRON-SIZED TIP USING ANISOTROPIC KOH ETCHING OF SILICON (100)

2015 ◽  
Vol 74 (10) ◽  
Author(s):  
Ummikalsom Abidin ◽  
Burhanuddin Yeop Majlis ◽  
Jumril Yunas
Keyword(s):  
Model Comparison ◽  
3D Structure ◽  
Three Dimensional ◽  
Size Variation ◽  
Anisotropic Etching ◽  
Etching Solution ◽  
Cavity Structure ◽  
Wet Anisotropic Etching ◽  
Etching Selectivity ◽  
Koh Etching

Microelectromechanical System (MEMS) are systems of micron-sized structures and typically integrated with microelectronic components. Bulk micromachining using wet anisotropic etching is able to etch silicon substrates to a desired three-dimensional (3D) structure, depending on the silicon crystallographic orientation. To date, MEMS components i.e. thermal, pressure, mechanical, bio/chemical sensors have been fabricated with wet anisotropic etching of silicon. This paper presents the fabrication of a 3D pyramidal cavity structure with micron-sized tip of silicon (100) using anisotropic KOH etching of w/w 45 % at 80 oC temperature. Volume percent of 10 % IPA as a less polar diluent is added to the KOH etching solution in saturating the solution and controlling the etching selectivity and rate. Smooth etched silicon surface of hillock free is able to be achieved with IPA addition to the KOH etching solution. A characteristic V-shaped cavity with side angle of 54.8 degrees has successfully been formed and is almost identical to the theoretical structure model. Comparison of two different silicon nitride window masks on the micron-size tip formation is also investigated. Under etch, over etch and etching selectivity, as common problems effecting the micron-tip size variation, are also addressed in this work. In conclusion, anisotropic KOH etching as a simple, fast and inexpensive bulk micromachining technique, in fabricating 3D MEMS structure using silicon (100), is validated in this work.

scholarly journals Three-dimensional particle tracking in microfluidic channel flow using in and out of focus diffraction

2015 ◽  
Vol 45 ◽  
pp. 218-224 ◽  
Author(s):  
Bushra Tasadduq ◽  
Gonghao Wang ◽  
Mohamed El Banani ◽  
Wenbin Mao ◽  
Wilbur Lam ◽  
...  
Keyword(s):  
Channel Flow ◽  
Particle Tracking ◽  
Three Dimensional ◽  
Microfluidic Channel

scholarly journals Oxygen transport and release of adenosine triphosphate in micro-channels

2015 ◽  
Author(s):  
Terry Moschandreou
Keyword(s):  
Oxygen Transport ◽  
Rapid Change ◽  
Microfluidic Channel ◽  
Permeable Membrane ◽  
Micro Channels ◽  
Free Region ◽  
Method Of Solution ◽  
Channel Tube ◽  
A Cell ◽  
The Right

The governing nonlinear steady equations for oxygen transport in a microfluidic channel are solved analytically. The Lagrange inversion theorem is used which admits complete integrable solutions in the channel. Considering a cell-rich and cell free region with RBCs and blood plasma, we obtain results showing clearly that there is a significant decrease in oxygen tension in the vicinity of an oxygen permeable membrane placed on the upper channel/tube wall and to the right side of it in the downstream field. The purpose of the membrane is to cause a rapid change in oxygen saturation as RBC’s flow through channel/tube. To the right of the membrane downstream the greatest amount of ATP is released. The method of solution is compared to numerical results. The analytical results obtained could prove useful for the corresponding time dependent problem in future studies.

Fabrication of LTCC Micro-fluidic Devices For Wireless Lab-On-A-Chip Applications

2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000085-000088
Author(s):  
Achraf Ben Amar ◽  
Houssem Eddine Amor ◽  
Hung Cao ◽  
Ammar B. Kouki
Keyword(s):  
Microfluidic Channel ◽  
Lab On A Chip ◽  
Dielectric Materials ◽  
Capacitance Measurement ◽  
Fluid Identification ◽  
Sensing Systems ◽  
Microfluidic Chamber ◽  
Micro Channels ◽  
Fluidic Devices ◽  
Electrical Permittivity

Abstract Low temperature co-fired ceramic (LTCC) based microfluidic sensors have been developed for biomedical and environmental sensing systems. This paper introduces a microfluidic chamber based on impedance spectroscopy measurements using LTCC technology for wireless Lab-On-A-Chip (LOC) applications. To overcome the channel sagging during the fabrication process, we used sacrificial carbon tapes as solid inserts, thus guiding the LTCC to follow their shape upon lamination and then formed micro-channels. The measurement chamber was a parallel-plate capacitive structure with 85 μm gap. This platform requires a small fluid sample of less than 4 μL. The sensor formed by the microfluidic channel and capacitance structure was characterized using different dielectric materials such as air, water and acetone. We hereby present the capability of LTCC-based systems in fluid identification by detecting their electrical permittivity using capacitance measurement.

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